Polymerizing vinyl compounds



. was

ronyunmzmc vmrr. courounn PATENT Orr-ice Leland c. Shrlyer, Charleston, w. Va, minor tocnrbidc \mi Carbon Chemicals col-pmtion, a corporation of New York No Drawing. Application January 29, 1932 I Serial No. 589,773

'1 Claims. (01. zoo-2)- Vinyl compounds can be polymerized to form resinous products for which various uses have been proposed. In general, the known methods for forming these resinous bodies from vinyl com- 5 pounds are treatment of the compounds with heat, actinic light, or a catalyst, or various combinations of these measures. Many catalysts have been suggested for promoting the polymerizing action. Among the catalytic substances in which have met with greatest favor for this purpose are lead tetraethyl and certain active oxidizing agents, such as dibenzoyl peroxide.

' It is the chief object of my invention to provide a new catalyst for polymerizing vinyl compounds,

and a process involving this catalyst. I have discovered that acetyl benzoyl peroxide (CHs.C0.0.0.CO.CsHs) I is an excellent polymerizing catalyst, especially go for the polymerization of vinyl halides such as vinyl chloride, vinyl esters of aliphatic acids such as vinyl acetate, vinyl propionate, vinyl butyrate etc., other vinyl derivatives, 'e. g. vinyl benzene (styrene), or related vinyl compounds, or EE- tures of these vinyl compounds. The resinous products obtained by polymerizing vinyl compounds in the presence of acetyl benzoyl peroxide are more stable with respect to exposure to heat and light, and they may be obtained more economically and quickly than by the use of previously known catalysts and processes.

Vinyl resins (by which are meant the above mentioned resinous products) have been previously made, and bymeans of various expedients have been rendered stable, heat and light resistant, and generally improved. One of the dimculties to be overcome in the preparation of a stable resin made, for example, with dibenzoyl peroxide as a catalyst, is the elimination of catalytic residues from the polymerized product. Although the amount of dibenzoyl peroxide used may be the minimum amount which will produce a satisfactory polymer, the decomposition of this peroxide in the process is never sufiiciently complete to eliminate catalytic residues from the resin, and additional measures must be adopted. Also, previously used catalysts, notably dibenzoyl peroxide, do not immediately efl'ect the polymerization and a certain time of inactivity is lost before the polymerization is initiated.

The new catalyst not only mitigates these objectionable features, but makes possible greater economy in the process of polymerization because it can be used in lower concentrations than other catalysts, and because the actual cost "of the new catalyst is lessthan that of dibenzoyl peroxide, for example. a

. The following example will serve to illustratethe invention:

Acetyl benzoyl peroxide was prepared by pass- 00 ing dry air or oxygen through a mixture of about four parts by weight of benzaldehyde and three parts by weightiofacetic anhydride until tests showed no further peroxide formation. A convenient test for indicating this formation is by measuring the liberation of iodine from a solution of potassium iodide. The mixture as produced may be used directly as the catalysts, or the acetyl benzoyl perioxide may be isolated from the mechanical strength. This resin was more stable to heat than similarly prepared resins made with dibenzoyl peroxide as a cataylst. 7

Among the advantages of my new catalyst as compared to other previously used catalysts, of which dibenzoyl peroxide is representative, are:

Smaller concentrations of catalyst are required. One part of acetyl benzoyl peroxide contains as much peroxide oxygen (assumed to be .the eflective part of the compound) as 1.34 parts of dibenzoyl peroxide; and in activity the .new catalyst surpasses dibenzoyl by a still wider margin than would be expected from this relation. I have found that a concentration of the new catalyst equal to between about 0.15% and about 0.3% of the weight of vinyl compounds present is suflicient, whereas approximately 1.0% of dibenzoyl peroxide was required. In general, I prefer to use less than about 1% of my new catalyst, and to operate the, polymerization process below about 40 C. I

There is less residual catalyst in the resins produced, hence, the stability of the resin is increased. This is true because less of the new 105 catalyst is used originally and because it is more completely utilized in the reaction due to its greater activity. Also, the residual amounts of the acetyl benzoyl peroxide catalyst may be more easily eliminated from the resin produced, be- 1m cause it is more active, and is more easily decomposable in the elimination.

'rhetimerequiredtoobtainequivalentresin yields with my new catalystislessthanthat necessary with other catalysts, because polymerization begins more quickly due to the greater activity of the new catalyst.

Acetyl' benzoyl peroxide may be used in conjunction with other catalysts, promoters and secelerating agents, and may be used in many modifications and variations of vinyl resin production processes.

I claim: 1. Process which comprises polymerizing chloride in the presence of acetyl benzoyl peroxide.

5. Process which comprisespolymerizing vinyl compotmds oi the group consisting of vinyl halides. vinyl esters of aliphatic acids, vinyl benzeneandmixturesoithesecompoundsinthe oi lessthan about 1% otacetylbenzoylperoxidebasedontheweightoi vinyleompounds.

8. Process for polymerizing vinyl compounds of the group consisting of vinyl halides, vinyl esters of aliphatic acids, vinyl benzene and mixtures of these compounds, which comprises subiecting the'vinyl compounds to a temperature below about 40 C. in the presence-o! less than about 1% by weight of acetyl benzoyl peroxide.

7. Process for polymerizing vinyl compounds of the group consisting of vinyl halides, vinyl 2. Process which comprises polymerizing mesters of aliphatic'acids, vinyl We gnd acetate in the presence of acetyl benzoyl peroxide. tures of these compounds; which comprises sub- 3. Process which comprises polymerizing a mixture of vinyl chloride and vinyl acetate in the presence of acetyl benzoyl peroxide.

4. Process which comprises polymerizing vinyl compounds of the group consisting of vinyl halides. vinyl esters of aliphatic acids, vinyl benzene and mixtures of these compounds in the presence of acetyl benzoyl peroxide.

jecting the vinyl compounds to a temperature below about 40 C. in the presence oi from about 0.15% to about 0.3% by weight 01' acetyl benzoyl peroxide.

LELAND C. BHRIVER. 

